Morning after pill to be taken lightly

Australian women may soon be warned that many morning after pills will not work if they weigh more than 80 kilograms, after a manufacturer unveiled plans for a similar alert for consumers in Europe.

The Therapeutic Goods Administration is believed to be considering the need to take formal action after French-based HRA Pharma, the manufacturer of the morning after pill Norlevo (which is sold in Australia), announced it would soon include advice that the medication may not be effective for women who weigh more than 75 kilograms, and is ineffective if they weigh more than 80 kilograms.

The company has acted after assessing the findings of a 2011 University of Edinburgh study of women using emergency contraception.

The study found that “the risk of pregnancy was more than threefold greater for obese women compared with women with normal body mass index, whichever [emergency contraception] was taken”.

The researchers found that the risk of pregnancy was particularly high if the emergency contraception contained the synthetic hormone Levonorgestrel, which is commonly used in over-the-counter morning after pills such as Plan B, Next Choice and Postinor.

But Professor Anna Glasier, a lead researcher in the University of Edinburgh study, told news.com their research was not designed to look specifically at the effect of weight on emergency contraception and was only based on evidence drawn from 1700 women.

“It is not my place to comment as to whether the company’s decision to change advice is premature,” Professor Glasier said, adding that previous analyses suggested there was no solid evidence to show that hormonal contraceptives were less effective in overweight women, though she admitted the quality of the studies was low.

Despite these reservations, HRA Pharma has proceeded with plans to issue the warning to its customers, though the manufacturer of another common morning after pill also using Levonorgestrel, Plan B One-Step, has not indicated any plans to follow HRA Pharma’s lead.